Coffee
The little kitchen area beside my desk has one of those coffee devices that those little restaurants and convenience stores use for coffee. 
The one where there is a base unit that drips coffee into a large dispenser which can then be carted away and a new one carafe stuck in.
Boy, that explanation sucked. Here, click on the picture to see it better.
Anyway, I asked around. We only have one carafe for it, and no one knows if it has EVER been cleaned. And it's not like one of those glass pots where everyone can see how filthy it is and someone eventually breaks down and sticks it in the dishwasher.
This is one of the reasons I've switched to tea at work.